1. Field of the Invention
The present invention relates particularly to a fixing apparatus which is usable in image forming apparatuses such as a copying apparatus and a printer apparatus in an electrophotographic system using a thermally melting developer and which fixes a developer to an output object.
2. Description of the Related Art
When a given image includes a color outside a gamut reproducible by a color image output apparatus, that is, a non-reproducible color, it is a general method to map colors outside the gamut in colors inside the gamut and output the colors. This is referred to as gamut mapping. As a method of the gamut mapping, some algorithms are known in accordance with a purpose of color reproduction. Since the gamut in a broad range is mapped in the gamut in a narrower range in many cases, the gamut mapping is sometimes referred to as gamut compression.
In a color image forming apparatus (MFP), an application is considered in which images rendered for printing output are stored inside, and reused for efficiency. The rendered image is gamut-compressed in accordance with the gamut of the printing output.
However, when the gamut-compressed image is reused, and color conversion is simply traced in reverse, the color of an original image cannot be restored. This is because as color values of C, M, Y (Bk is sometimes independent) which are color components of subtractive mixture of a certain printer, a plurality of color values exist in an original gamut-compressed space. That is, the color values of C, M, Y (, Bk) are not necessarily the color values of the original color space obtained by inverse conversion in which one correct answer is obtained.